Extra high early-strength portland cement

ABSTRACT

This invention is to provide Portland cement having extra high 1-day compressive strength composition of which is: the particular lime saturation degree 0.95-1.03, Cr203 content 1.2- 2.6 percent by weight and (Al203+Fe203) content 7.0-8.6 percent by weight, weight ratio of Al203/Fe203 being 1.65 + OR 0.50.

AU 112 EX Uno et al. 1 1 Mar. 14, 1972 [54] EXTRA HIGH EARLY-STRENGTH 3,298,843 1/1967 Asano 106/100 PORTLAND CEMENT 3,194,673 7/1965 Schedel .....106/l00 2,204,959 6/1940 Frenkel.... .....l06/100 [72] Inventors: Tatlulro Uno, Kanagawa; M 1,829,082 10/1931 Bergen 106/101 Mochizuki, Tokyo, both of Japan [73] Assignee: Onoda Cement Company, Limited, Onoda, FOREIGN PATENTS 0R APPLICATIONS Yamaguchi Prefecture, Japan 12,741 1966 Japan 106/100 [22] Filed: July 1969 Primary Examiner'lobias E. Levow [21] Appl. No.: 841,794 Assistant Examiner-W. T. Scott Attorney-Fidelman, Wolfe & Leitner [30] Foreign Application Priority Data 57 STRA July 20, 1968 Japan ..43/51340 This invention is to provide pordand cement having extra high l-day compressive strength composition of which is: the par- U.S. ticular aturation degree C O co t [5 Illt- Cl- ...C04b percent by weight and 3 con! [58] FieldofSearch 106/100, 101, 102, 89 7,043.6 percent by weight, weight ratio of Al,O;/Fe 0, beflg 1.651050. [56] References Cited w 4 Claims, 3 Drawing Figures UNlTED STATES PATENTS 3,447,937 6/1969 Hersey et al. ..l06/l02 pressiue Strength (kg /cm") 3' a O o C' R-Z-d -U Com Particular LSD in clinker FIG. 3

INVENTORS fa'l'wsaao \(m W\asa.+sk3 Mamma- EXTRA HIGH EARLY-STRENGTH PORTLAND CEMENT BRIEF SUMMARY OF THE INVENTION BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS The figures show the results of experiments.

FIGS. No. l-No. 3 show the changes in the l-day compressive strength in accordance with variations in Cr,O content, fic i atfiepa) ent ta s v n i l r li Saturation ee,

DETAILED DESCRIPTION Table No. I shows chemical analysis values of raw materials see P F Fft l .91913557 33 3? et n men!- TABLE 1 Percent Raw materials Ig. loss 810- A120: FezOa CnOi CaO MgO S0: N810 K Total Lime stone 4:3. 7 0. 3 0. 3 0. 1 55. 2 0. 6 100. 2 ay 7.7 60.5 16.5 17.1 1.6 3.2 1.88 1.42 99.8 Sillceous material.-. 3. 6 83. 2 8. 3 3. 2 0. 4 0. 9 0. 00 0. 16 99. 4 Copper slag... 4. 4 36. 8 8. 1 47. 4 6. 2. 4 0. 60 0. 83 97. 0 Chromite... 0.0 4.4 26.4 15.2 33.8 0.8 17.1 97.7

Gypsum 21.2 0.2 32.6 46.1 100.0 Serpentinite l2. 2 39 1 32. 8 11. 1 2. 0 33. 3 100. 6

cially in the rotary kiln of the ordinary type, and insufficient burning results in increase in free lime. Accordingly, l-day compressive strength of Portland cement can not attain to more than lOO kg./cm. by the Japanese Industrial Standards,

JIS R 5201 (1964). Recently, however, civil engineering and construction circles are in need of Portland cement having 0 extra high l-day compressive strength upwards of 150 kg/cm. by JIS R 5201(1964).

The primary purpose of this invention is to provide Portland cement having l-day compressive strength upwards of I50 kg./cm. and other incidental purposes will be made clear from the following description. The mineral composition of early-strength Portland cement clinker consists of alite and interstitial materials which consist of glass phase, C AF phase and QA phase (here and hereinafter C,A and F represent CaO, A1 0 and Fe O respectively,) and it is generally known that what contributes to the strength of Portland cement clinker is mainly alite. Alite is the solid solution of C 5 (here and hereinafter S represents SiO- containing solid solution of such impurities as Mg 0. A1 0 Fe O etc. up to approximately l-2 percent by weight. It has recently been made clear that the strength of clinker varies notably according to kinds of such impurities in solid solution.

Accordingly, the inventors of this invention have been conducting studies with a view to producing extra high l-day compressive strength Portland cement, by including solid solution of Cr O in addition to the solid solution of the above mentioned impurities in the composition of alite, so as to improve its hydraulic characteristic.

Studies to produce early compressive strength Portland cement from clinker which is produced by adding Cr O to raw materials for clinker and burning the mixture have already been reported, but those studies point out that the maximum 3-days compressive strength is attained where Cr O content in clinker is in the neighborhood of 1 percent by weight, and that early compressive strength of Portland cement cannot be obtained, if Cr O content in clinker is increased or decreased from the above mentioned per centage (1 percent).

The present inventors, however, have come out with the 'findings after systematic studies in regard to the chemical composition of early-strength Portland cement clinker that 5 the maximum solid solubility of Cr O, is the highest in interstitial materials, followed by belite, while alite is the lowest in interstitial materials, and that where the content ofCr O in alite is increased, l-day compressive strength of early strength Portland cement is augmented. and furthermore that where the content of Cr O in clinker is 1.2-2.6 percent. l-day compressive strength, not to speak of 3-days compressive strength, increased sharply.

Below, only representatives of many experiments that have been conducted will be reviewed.

Where the component materials shown in Table No. l were used, 0,0, content was altered to meet the below-mentioned conditions. The mixed materials were pulverized so as to pass 99 percent by weight through 88 p. sieve. (Hereinafter numerical values are by weight unless otherwise mentioned).

CONDITION 1.

In order to make the composition of clinker substantially a mixture ofC S, C AF and GA (note: C 5 is not included), the particular lime saturation degree (hereinafter abridged as particular L.S.D.) was worked out as follows:

Ca0 1.39 M30 00 2.80 stow-0.79 ch01) 1.65 A 1.0. 0.35 Fez0a The above particular L.S.D. was worked out by the following calculation:

On the supposition that the composition of cement minerals consists of C S-C A-C AF system and L.S.D. of said composition is calculated by Bogues method so as to be equal to 1.00, .the L.S.D. may be shown as follows:

Particular L.S.D. m

where M=MgO mole and Cr=Cr O mole. When C,S,A,F,M, and Cr are represented by weight per cent, the above equation (1) is induced from the equation (3 CONDITION 2. AIzOgi' Fe O =7.4% Iron modulus Al,O /Fe,O =-l .65

changes in l-day compressive strength in accordance with the 10 varied content of Cr,O;, are shown in FIG. 1.

consisting of particular L.S.D. 1.00 and Cr- O, 2.0 percent was altered, and clinkers were made in the same manner described in the above, to which gypsum was added and the mixture was pulverized. The strength tests were conducted on the cement thus produced. The results are shown in Table 3, and the change in l-day compressive strength in accordance with the varied contents of R is show in F IG. 2.

it became clear from Table 3 and FIG. 2 that extra high early-strength Portland cement having 1-day compressive strength upwards of 150 kg./cm. was obtained where particular L.S.D. l00 and Cr O 2.0%, R 0 content 7.0-8.6%,

TABLE 2-a Percent Particular F-CaO, Sample Number 810 A1103 F6201 CnOi C80 MgO N820 K10 Total SM I L.S.D. percent 22. 0 4. 6 2. 8 0. 0 68. 3 1. 6 0.44 0. 36 100. 0 3. 0 1. 6 1. 00 0. 5 21.4 4.6 2.8 0.7 68.2 1.5 0.37 0.29 99.9 2.9 1.6 1.00 0. 21.2 4.6 2.8 1.0 68.3 1.6 0.29 0.24 99.9 2.9 1.6 1.00 .0.6 21. 1 L 6 2. 8 1. 2 68. 5 1. 6 0. 26 0. 18 100. 1 2. 8 1. 6 1. 01 0. 6 20.9 4.6 2.8 1.4 68.5 1.5 0.23 0.17 100.1 2.8 1.6 1.01 0.6 20.7 4.6 2.8 1.6 68.6 1.6 0.21 0.15 100.2 2.8 1.6 1.01 0.6 20.6 4. 6 2. 8 2. 0 68. 2 1. 5 0. 16 0. 99. 8 2. 8 1. 6 1. 00 0. 9 20. 2 4. 6 2. 8 2. 6 68. 7 1. 6 0.08 0. 03 100. 4 2. 7 1. 6 1. 00 0. 7 20.0 4.6 2.8 2.7 68.5 1.5 0.06 0.01 100.2 2.7 1.6 1.00 2.6 19. 8 4. 6 2. 8 2. 9 68. 6 1. 6 0. 02 0.00 100. 2 2. 7 1. 6 1. 00 2. 4

TAB LE 2-b Specific surface Compressive strength, kg./cm. Observation through a microscope Sample (Blaine) Number cm.'/g. 1 day 3 days 4 weeks Color of alite Others 1 4, 690 105 204 422 Colorless Bellte (C28) When mixed was not inmaterials eluded. was burned for minutes at 1,500 C. Bellte and F-CaO was Included in clinker. 4, 550 126 235 ....do

4, 670 140 256 ..do 4, 630 150 246 .00-. 4, 620 177 260 .do. 4, 610 199 284 do 4,620 197 292 ...do. 4,700 201 275 .do 4,550 138 230 Bellte and F- CaO was included. 4,630 122 210 440 ....do .do

TABLE 3 Specific Oneday Percent surface compressive Particular F. CaO, (Blain strength 8101 A110: F6203 CnO; CaO MgO N s10 K20 Total R10: 8M IM L S.D. percent crnfl/g kg./cm. 21. 6 3. 6 2. 2 1. 9 69. 0 1. 6 0 0. 01 99. 9 5. 8 3. 7 1. 6 1. 00 1. 0 4, 580 117 21. 1 4.2 2.6 2. 0 68.6 1.5 0. 06 0.01 100. 0 6.8 3. 1 1.6 1. 00 0.7 4,520 125 20.8 4.4 2. 7 2.0 68.6 1.6 0. 11 0.06 100. 1 7.1 2.9 1. 6 1. 00 0.8 4,660 167 20.6 4.6 2.8 1.9 68.4 1.6 0.15 0.09 99.9 7.4 2.8 1.7 1.00 0.9 4,560 187 20.4 4. 7 2.8 1. 9 68.4 1.6 0.15 0.10 100.1 7.6 2. 7 1.7 1.00 0.8 4,680 195 20.1 4.9 3.0 1.9 68.2 1.6 0.22 0.16 100.0 7.9 2.6 1.6 1.01 0.7 4,660 190 20.1 5.0 3.0 1.9 67.9 1.5 0.23 0.20 99.8 8.0 2.1 1.7 1.00 0.6 4,570 185 19. 8 6. 2 3.1 1. 9 67. 8 1. 6 0. 26 0.29 99. 8 8. 3 2. 4 1. 7 1. 01 0.6 4. 610 176 19. 6 5. 4 3. 3 1. 9 67. 7 1. 5 0. 31 0. 35 100.1 8. 7 2. 2 1. 6 1. 01 0.3 4, 630 141 it is clear from Table 2 and FIG. 1 that clinkering was best facilitated, and Portland cement, having l-day compressive strength upwards of 150 kg./ c r n. was obtained wherepartjeular L.S.D. 1.00. (Al O +Fe O content= 7.4 percent. Al O /Fe O ratio= 1.65 and C; content= 1.2-2.6%, more preferably 1.6-2.4%.

Where Cr O; contents=less than 1.2 percent, the content of 0,0, solid solution in alite was insufficient and, therefore, 1- day compressive strength did not increase satisfactorily, and when Cr O content=more than 2.6 percent, alite decomposed to belite and CaO and l-day compressive strength of cement dropped sharply, because C130 content was over the limit of solid solution of alite and of interstitial materials.

Next, mixed materials were prepared so that the content of R O Al O +Fe O (incase of AhOa/Rz O =1.65) in clinker cordingly,

preferably 7.2-7.8%, and A1 0 1.65.

in other experiments, it was found that where the C 0, content in clinker varied in the range of 1.2-2.6 percent, the result of the same tendency was observed, and the same was true when the ratio ofAl O /Fe O; varied 1.65:0.50.

Where R 0 content was less than 7.0 percent, solid phase reaction took place partially or uneven chemical reaction took place, due to the shortage of interstitial materials content, and therefore, Cr O was unevenly melted in alite, and l-day compressive strength of cement dropped. On the other hand, where R 0 content was more than 8.6 percent, interstitial materials content which contained more Cr O than alite increased, causing the Cr,O;, content in alite to decrease, and also the relative content of alite in clinker decreased, and acl-day compressive strength dropped.

Furthermore, in order to test changes in the 1-day compresmaterial, copper slag and chromite are mixed so as to make sive strength of cement mortars in which particular L.S.D. clinker P as memlm'ed 'above and the mixedvaried, the following three different clinker compositions were materials are pulverized so as to P 99 P y weigh! through 88 p. sieve, and then they are burned to make clinker prepared, namely,

1 C O Al,O +Fe O =7 0%, Al,() /F =1 65 at l450-l600 C. Gypsum (22-35% as S0,) 3) IS added to 2. Cr,0,=l .0%, Al,O +Fe,O,=7.0%, Al,O /Fe,O,=l .65 clinker and the mixture is pulverized. 1n the course of burning,

3, C O Al o +i= o =7,3%, A1 O /Fe O =1,65, part of C O; composition may evaporate, so it is recomar d cements of three kinds were produced in the same mended 10 mix chromite about 10 percent more 10 make up manner described above. Tests of their 1-day compres- 10 decrease l 'z a compositionsive strength were conducted on the cement mortars. EX"?! hlgh eal'ly'strength POnland cement Produced Their results are shown in FIG. 3. The test results shown cmding this invention has not l/ P F in FIG. 3 were numbered so as to correspond to the numsnength upwards 150 S- but its "8 8 sn'cnglh ls b fth b i d li k stabilized, and its contractibility, its chemical resistance and From the results, it became clear that due to increase in the l 5 its ll/"liability i favm'ably with y Portland particular L.S.D., 1-day compressive strength rose at the higher rate, especially when Cr O, content increased, and that the rate of increase became greater when the particular L.S.D. 0.95 or thereabout. Furthermore, it was found that when the iankiular and upward-5, lime changes Materials consisting of lime stone, clay, silicious material,

EXAMPLE:

place in the 1-day compressive strength. But when the particucopper slag, chromite, as mentioned in Table No. l were lar became higher than 1-00, burnability of clinker mixed at the rate of l,000:0.076:0.l30,011:0.048 respectivebecame dlfi lCLIlI 10 the 8X16! that clinker could not be burned ly, and the mixed materials were pulverized so as to pass 99 in a rotary kiln. For this reason, the highest value of the particular L.S.D. is preferably set at 103. Next, where the parmaterials were placed in a rotary kiln having the length of 8.34

percent by weight through 88 p. sieve. The pulverized, mixed ticular L.S.D. less than 0.95, belite content increased, and as m., inside diameter of 0.45 m., placed at an incline of 5/100,

the content of Cr,0, solid solution in belite which was greater with the number of rotations =60 rpm. and were burned at than that in alite and the content of Cr,0, solid solution in over 1,500 C. into clinker and kg./hr. of clinker were alite decreased, 1-day compressive strength of cement 30 roduced. Gypsum (2.5 percent as S0,) as shown in Table dropped sharply. No. l was added, and the mixture was pulverized by ball mill To summarize the experiments results, it was made clear (1 gth=37 cm" h i id di =44 cm" h number f that where the cement produced from the clinker, composirotations 45 rpm.) The cement thus obtained was tested in tion of which was: the particular L.S.D. 0.95-1.03, Cr,0,= accordan e with JISR 5201 (1964) i re e t of owd finel.22.6%, (Al,O,,+Fe,O 7.0-8.6%, Al,O;/Fe,O l.65 35 ness, setting and compressive strength. The obtained results 0.50, pulverized, after gypsum was added, to the extent that were as shown in Table No.4.

TABLE 4.COMPOSITIONS 0F CLINKER Percent Particular F. 6:10, SiOz A120; FezOr CrzOr C80 MgO NagO K20 Total L.S.D. percent HM SM IM Bellte was not observed through 20. 1 4. 9 2. 9 2. 1 68. 2 1. 5 0. 22 0.16 100.1 1. 01 0. 9 2. 44 2. 6 1. 7 a microscope Setting test of cement Degree of fineness of cement Strength test of cement Initial Final Bendi stre th, k .lcm. Compressive strength, kg./cm.*

Amount setting setting Residue over Specific surn8 n8 8 of water, time, time, Flow, 88 .1 sieve, face (Blaine), percent hr. min. hr. min. mm. wt. percent cmJ/g. 1 day 3 days 7 days 4 weeks 1 day 3 days 7 days 4 weeks the value of specific surface area by the Blaine method was What is claimed is: 4,6001100 cm./g., its early compressive strength was high up 1. Extra high early-strength Portland cement prepared by to 150-210 kg./cm., and that where the value of specific surpulverizing clinker having compositions: the particular L.S.D. face area by the Blaine method was 5,600tl00 cm./g., its 0.95-1.03, Cr O content 1.2-2.6% by weight, (Al,0,+

early compressive strength was extra high up to 220250 z a) content 70-86% by igh nd Weigh ratio of kg./cm.. in this case, the content of gypsum to be added to z a/ z F clinker is preferably 2.2-3.5 percent as So in cement. 2. Extra high early-strength Portland cement according to When 1-day compressive strength upwards of 160 kg./cm," claim 1, in which said clinker has compositions: the particular ,is required under this invention where the value of the specific 2 Come!!! 12-16% y g surface are by the Blaine method is 4,6001100 cm."/g., the a t 9911mm y weight and Weigh! composition of clinker could be: particular L.S.D. ratio z a 2 097-103 3 0 =1 2 2 c s- 0 1 7 240 3. Extra high earlystrength Portland cement according to c r 0 55 030 panicular 093 1 65 claim 1, in which said clinker has compositions: the particular (1 0 =1 2 4% .r- =7 0 3 Mags/F620a L.S.D. 0.98-1.02, C 0, content 1. 6-2.4% by weight, =1 6510.30, and furthermore, where the value of specific sur- Fezofl) content= y Weigh and Weight ratio face area by the Blaine method is 4,6003100 cm. /g., and ce- =9 ment having OM43), compressive strength of 190410 4. Extra high early-strength Portland cement according to laim l in which said clinker has com sitions: the articular kg./cm. is required, the clinker composition must be. particuc W P lar L.S D. 0.98-1.01, cr,o,=1.6-2.4%, A1,0,+Fe,0, =7.2- 12 Q:9i" FIEQai BEELififift ls l'ji 8.0%, A], C ll-e 0 =b 1551010 (Al O +Fe O content= 7.2-8.0% by weight and weight ratio in order to produce extra high early-strength Portlandce- M108, F 90514553020 ment according to this invention, lime stone, clay, silicious 7203 v ioiozv om 

2. Extra high early-strength Portland cement according to claim 1, in which said clinker has compositions: the particular L.S.D. 0.97-1.03, Cr2O3 content 1.2-2.6% by weight, (Al2O3+Fe2O3) content 7.2-8.0% by weight and weight ratio of Al2O3/Fe2O 1.65 + or - 0.30.
 3. Extra high early-strength Portland cement according to claim 1, in which said clinker has compositions: the particular L.S.D. 0.98-1.02, Cr2O3 content 1.6-2.4% by weight, (Al2O3+Fe2O3) content 7.0-8.6% by weight and weight ratio of Al2O3/Fe2O3 1.65 + or - 0.30.
 4. Extra high early-strength Portland cement according to claim 1, in which said clinker has compositions: the particular L.S.D. 0.98-1.01, Cr2O3 content 1.6-2.4% by weight, (Al2O3+Fe2O3) content 7.2-8.0% by weight and weight ratio of Al2O3/Fe2O3 1.65 + or - 0.20. 